A pilot study for diagnosis of genital Chlamydia trachomatis infections by polymerase chain reaction among symptomatic Indian women.

Background: Chlamydia trachomatis is the most common bacterial etiology of sexually transmitted infection. Aim : A pilot study was designed using PCR for amplification and detection of a specific 517 bp sequence of the common endogenous plasmid of C. trachomatis from clinical swab specimens obtained from symptomatic female patients attending STD clinics of AIIMS and Regional STD Teaching, Training & Research Center, Safdarjang Hospital, New Delhi. Methods: 97 patients were recruited in the study, and endocervical swabs were collected following standard procedures. The samples were analyzed by PCR and direct fluorescence antibody (DFA) for detection of C. trachomatis, and the sensitivity, specificity, PPV and NPV of PCR were calculated taking DFA as gold standard. Results: Out of 97 samples tested, 9 were positive for C. trachomatis by PCR. 1 PCR positive patient was negative by DFA although a total of 11 patients were positive by DFA. The sensitivity, specificity, PPV and NPV of PCR with reference to DFA was 72.73%, 98.84%, 88.89% and 96.59%, respectively. This PCR had high specificity and NPV for detection of C.trachomatis. Conclusions : In light of the introduction of enhanced syndromic approach, which involves the use of laboratory techniques (wherever possible) to confirm clinical diagnosis, a diagnostic PCR with high specificity and NPV is particularly valuable for determination of etiological diagnosis and hence contribute to judicious use of antimicrobials in the community.

The role of a commercial enzyme immuno assay antigen detection system for diagnosis of C. trachomatis in genital swab samples.

In the present pilot study, endocervical and urethral swabs collected from 100 patients attending sexually transmitted disease (STD) clinics and regional centre for STD in two referral hospitals in New Delhi were analyzed by enzyme immune assay (EIA), polymerase chain reaction (PCR) and direct fluorescent antibody (DFA) for detection of C. trachomatis. It was found that EIA could detect a very low number of cases (3/100) as against DFA (11/100) and PCR (9/100). Thus, in spite of the widespread availability, lower cost and ease of performance of the enzyme-linked-immunosorbent serologic assay, the present study highlights the need to employ sophisticated diagnostic tools like DFA and PCR for detection of Chlamydia trachomatis in STD patients.

Sensibilidade da técnica de imuno-histoquímica em fragmentos de sistema nervoso central de bovinos e equinos naturalmente infectados pelo vírus da raiva / Sensitivity of the Immunohistochemistry technique in central nervous system fragments of cattle and horses naturally infected by rabies virus

A raiva é uma zoonose viral que acomete o sistema nervoso central (SNC) de mamíferos, considerada um grave problema de saúde pública. Herbívoros (bovinos e equinos) são frequentemente acometidos pela in-fecção após serem atacados por morcegos hematófagos (Desmodus rotundus). A técnica de imunofluorescência direta (IFD) realizada em tecidos frescos, recomendada pela Organização Mundial de Saúde (OMS), é utilizada para o diagnóstico da raiva. A técnica de imuno-histoquímica (IHQ) é utilizada para detectar antígenos em tecidos fixados, pelo uso de anticorpos monoclonais/policlonais. O objetivo deste trabalho foi avaliar a sensibilidade da IHQ na detecção de antígenos do vírus da raiva em amostras de SNC de herbívoros fixadas em formol, analisando a distribuição antigênica em diferentes fragmentos do SNC. Os resultados demonstraram concordância das técnicas de IFD e IHQ. A IHQ mostrou maior sensibilidade em amostras de bovinos em relação às de equinos, especialmente quando realizada em fragmentos de cerebelo e tronco encefálico. A detecção de antígeno nestes fragmentos foi mais consistente para ambas as técnicas, nas duas espécies. Estes resultados demonstram que a IHQ pode ser empregada para a vigilância epidemiológica da raiva, entretanto, recomenda-se cautela ao se empregar a IHQ para diagnóstico de doença em herbívoros, especialmente quando o fragmento encaminhado ao laboratório for apenas o hipocampo.

Rabies is a viral zoonosis that causes disease in the central nervous system (CNS) of mammals and it is considered a serious problem of public health. Herbivorous (bovines and equines) are often infected after being attacked by vampire bats (Desmodus rotundus). The direct fluorescent antibody technique is used as a diagnostic test to detect viral antigens in fresh tissues and is recommended by the World Health Organization. The immunohistochemistry technique (IHC) is used to detect the viral antigen through the use of monoclonal/policlonal antibodies in formalin-fixed tissues. The aim of this work was to evaluate the sensitivity of the IHC in samples of CNS of herbivorous fixed in formol, analyzing the antigenic distribution in different fragments of the CNS. The results demonstrated good agreement between the two techniques for the rabies diagnosis. The IHC presented higher sensitivity in samples of cattle comparing to horse samples, especially in fragments of cerebellum and brain stem. These fragments demonstrated to be more suitable for antigen detection by both techniques in the two species. These data demonstrate that the IHC is suitable for rabies vigilance yet cautions should be taken in examining cattle and horses samples, when the submitted specimen is only the hippocampus.

Vasculite cutânea de pequenos vasos: etiologia, patogênese, classificação e critérios diagnósticos - Parte I / Small vessel cutaneous vasculitis: etiology, pathogenesis, classification and diagnostic criteria - Part I

Vasculite é a inflamação da parede dos vasos. Pode variar em gravidade desde doença autolimitada de um único órgão até doença grave com risco de morte por falência de múltiplos órgãos. Existem várias causas, embora só se apresente por poucos padrões histológicos de inflamação vascular. Vasos de qualquer tipo e em qualquer órgão podem ser afetados, resultando em ampla variedade de sinais e sintomas. Diferentes vasculites com apresentações clínicas indistinguíveis têm evolução e tratamento muito diferentes. Essa condição representa desafio para o médico, incluindo classificação, diagnóstico, exames laboratoriais pertinentes, tratamento e seguimento adequado. Neste artigo são revistos a classificação, a etiologia, a patogênese e os critérios diagnósticos das vasculites cutâneas.

Vasculitis is an inflammation of vessel walls. It may range in severity from a self-limited disorder in one single organ to a life-threatening disease due to multiple-organ failure. It has many causes, although they result in only a few histological patterns of vascular inflammation. Vessels of any type in any organ can be affected, a fact that results in a broad variety of signs and symptoms. Different vasculitides with indistinguishable clinical presentations have very different prognosis and treatments. This condition presents many challenges to physicians in terms of classification, diagnosis, appropriate laboratory workup, treatment, and the need for careful follow-up. This article reviews the classification, etiology, pathology and diagnostic criteria of cutaneous vasculitis.

Evaluation of the VIDAS chlamydia test detect Chlamydia trachomatis in samples from urogenital tract / 中华检验医学杂志

Objectives To evaluate bioMerieux VIDAS(Vitek Immune Diagnositc Assay System) Chlamydia test (CHL) and to determine its performance(sensitivity and specificity) by comparing with cell culture. Methods C. trachomatis in urogenital samples was detected by both cell culture and VIDAS CHL. The different results were confirmed by direct fluorescent antibody assay (DFA). The sensitivity to C.trachomatis serotype D and E stocks was alsode tected with VIDAS CHL and cell culture. Results C.trachomatis was found in 33 (20.2%) of 163 urogenital samples by cell culture in coutrast to in 44(27.0%) by VIDA CHL. As the expanded gold standard was defined as either cell culture positive or cell culture negative and both CHL and DFA positive, the sensitivity was 80.5% and 95.3% and the specifiaty were 100% and 97.6% in cell culture and VIDAS CHL, respectively. In the sensitivity test, C. trachomatis serotype D was tested positive at the highest dilution of one to 102 400 dilution and serotype E was at one in 51 200 by cell culture. However, both serotype D and E were tested positive at the highest dilution of one to 6 553 600 by VIDAS CHL. Conclusions Comparing with the expanded gold standard, VIDAS CHL is sensitive and specific for C.trachomatis in urogenital specimens, with simple and short running hours (1 h). First catch urine (FCU), which avoids the painful male swab collectionin male patients, could also be used as specimen in VIDAS CHL test.